Recently, the National Time Service Center Zhang Shougang and Jiang Haifeng femtosecond optical comb led by its research team made significant progress in ultra-stable laser research, the relevant technical indicators have reached the international advanced level. Using a self-designed and developed electro-optic modulator, the team dramatically reduced the residual amplitude modulation noise in the conventional laser PDH lock-in technique and successfully locked the 1555 nm fiber laser to the resonant frequency of the ULE optical reference cavity Frequency. By comparing two sets of ultrastable laser systems located in different laboratories, we measured the ultra-stable laser beat frequency of 185mHz and short-term frequency stability of 7 × 10-16. The result will be published in Chinese Physics letters , The electro-optic modulator experimental results published in the American Optical Society Journal Optics Letters, and has applied for PCT international patent "PCT / CN2016 / 070552" and the United States patent. Ultra-stable lasers have important applications in optical frequency standard, ultra-stable microwave sources, ultra-precision spectroscopy, gravitational wave detection and other fields, and are one of the competitive focuses of international precision metrology research. At present, the ultrastable laser system developed by the team has been successfully applied in the development of ultra-stable photo-generated microwaves. It will also provide favorable support for the development of optical clock systems, reference fountain clocks, and optical fiber frequency transmission undertaken by the national time service center. Figure 1 Noise Effects of PDH Laser Frequency Locking with Different Electro-Optic Modulators (Homemade - Red, Commercial - Black) Figure 2 Ultra-stable laser frequency stability Figure 3 ultra-stable laser line width (measured laser beat frequency 185mHz, measured test resolution 123mHz, set the test resolution of 125mHz) Display Stands,Oem Showcase,Wall Mounted Showcase Fabrication,Display Showcase FCX Metal Structure Co., Ltd. , https://www.fcxmetal.com
November 14, 2021